Lumps on skin

Question
Hi,
We live on a Navy base on Andros Island, Bahamas- and have to fly to the states to have a vet check-so i thought it might be best to ask a question here first.
I have a rescue dog who is said to be a collie/sheltie/australian shepherd mix. Over the past 2-3 weeks she has gotten these 2 bumps- one on the inside of her leg and the other at her chest near the inside of her leg. The one near her groin grew first, and also has seem to enlarge. It is a bump above the skin, as I can easily move it. She is a thin dog-the last time we weighed her she was 26 pounds, and every now and then she throws up a yellowish liquid in the morning (i read that this could just be acid build up).Of course I thought the worse, and jumped to cancer-so I decided to look up signs. This made it worse since I am a hypochondriac myself.The lumps are about pea size.She doesn't seem to have any other outward problems- she's always been a quiet, lazy dog-playing with our australian cattle dog/collie when she pleases.
I'm not sure if you are the right person to ask, all of you have so much information! I hope I have not wasted  your time. Is it possible she has cancer, or am i getting ahead of myself? (I can send a picture if it helps?)
Thanks, Davina

Answer
Hi Davina!

First, and foremost, I am not a Veterinarian,as you know.  so this is only a guess. I can't say for sure it's not cancerous but it sounds doubtful. It sounds to me more like a sebaceous cyst. These are usually painless, slow-growing small bumps or lumps that move freely under the skin.  I wouldn't worry too much about it, and the next time you take a trip inland, you could have a Vet look at it.  As I said, this is just my guess, and if it were me I would keep an eye on it and see if there are any changes.  If they tend to grow rapidly or seem infected, then I would definitely take her in.
Good luck and God bless,
Becky